Agamem Microelectronics Inc. PRELIMINARY AA1850 HIGH-SIDE CURRENT MONITOR ■ DESCRIPTION The AA1850 is a high side current sense monitor. It takes a high side voltage developed across a current shunt resistor and translates it into a proportional output current. A customer defined output resistor converts the output current into a reference voltage. It operates over a wide input voltage range, from 2.5V to 20V and makes it suitable for many applications. A minimum operating current of 4uA, combined with its SOT23 package make it a right solution for portable equipment. ■ FEATURES • Low cost and accurate high-side current monitor. • Up to 2.5V sense voltage. • 2.5V – 20V supply range. • 4uA quiescent current. • 1% typical accuracy. ■ APPLICATIONS • Battery chargers • DC motor control • Over current monitor • Power management • Programmable current source ■ BLOCK DIAGRAM ©Copyright Agamem Microelectronics Inc. 1 www.agamem.com.tw 2008/4/8 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY AA1850 HIGH-SIDE CURRENT MONITOR ■ PIN DESCRIPTIONS PIN NO. 1 PIN NAME VSENSE- PIN FUNCTION Connect load 2 VSENSE+ Supply voltage 3 IOUT Output current, proportional to VIN — VLOAD ■ ABSOLUTE MAXIMUM RATINGS PARAMETER SYMBOL RATING UNIT Voltage on any pin VOP -0.6~+ 20 (relative to IOUT) V Continuous output current IOUT 25 mA Continuous sense voltage (*2) VSENSE -0.5 ~ +5 V Operating temperature TOPR -40 ~+ 85 °C Storage temperature TSTG -55~+125 °C Pd 450 (TA = 25°C，derate to zero at 125°C) mW Package power dissipation SOT23 Operation above the absolute maximum rating may cause device failure. Operation at the absolute maximum ratings for extended periods may reduce device reliability. ©Copyright Agamem Microelectronics Inc. 2 www.agamem.com.tw 2008/4/8 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. AA1850 Agamem Microelectronics Inc. PRELIMINARY HIGH-SIDE CURRENT MONITOR ■ ELECTRICAL CHARACTERISTICS TA = 25°C, VIN = 5V, Rout = 100Ω. SYMBOL VIN Iout (*1) PARAMETER VCC range Output current VSENSE (*2) Sense voltage IsenseVSENSE- input current Acc Accuracy Gm Tran conductance, IOUT / VSENSE BW Bandwidth CONDITIONS VSENSE =0V VSENSE =10mV VSENSE =100mV VSENSE =200mV VSENSE =1V RSENSE =0.1Ω VSENSE =200mV LIMITS MIN TYP MAX 2.5 20 1 4 15 90 104 120 0.975 1.002 1.025 1.95 2.0 2.05 9.6 9.98 10.2 0 2500 100 -2.5 2.5 1000 0 VSENSE = 10mV, PIN = -40dBm (*3) VSENSE = 100mV, PIN = -20dBm (*3) 300 2 UNIT V µA µA mA mA mA mV nA % µA/V kHz MHz *1 Includes input offset voltage contribution *2 VSENSE is defined as the differential voltage between VSENSE+ and VSENSEVSENSE = VSENSE+ - VSENSE= VIN - VLOAD = ILOAD x RSENSE *3 -20dBm=63mVp-p into 50Ω ©Copyright Agamem Microelectronics Inc. 3 www.agamem.com.tw 2008/4/8 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. AA1850 Agamem Microelectronics Inc. PRELIMINARY HIGH-SIDE CURRENT MONITOR ■ APPLICATION CIRCUIT Rsense Vin 2 1 Rload 3 Vout Rout Where RLOAD represents any load including DC motors, a charging battery or further circuitry that requires monitoring, VSENSE can be selected on specific requirements of accuracy, size and power rating. The following lines describe how to scale a load current to an output voltage. VSENSE = VIN - VLOAD VOUT = 0.01 x VSENSE x ROUT (E1) E.g. A 1A current is to be represented by a 100mV output voltage: A. Choose the value of RSENSE to give 50mV > VSENSE > 500mV at full load. For example VSENSE = 100mV at 1.0A. RSENSE = 0.1/1.0 => 0.1Ω. B. Choose ROUT to give VOUT = 100mV, when VSENSE = 100mV. Rearranging E1 for ROUT gives: ROUT = VOUT /( VSENSE x 0.01) ROUT = 0.1 / (0.1 x 0.01) = 100Ω ©Copyright Agamem Microelectronics Inc. 4 www.agamem.com.tw 2008/4/8 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. AA1850 Agamem Microelectronics Inc. PRELIMINARY HIGH-SIDE CURRENT MONITOR ■ ORDERING INFORMATION ORDER NO. PACKAGE PACKING ONE REEL Q’TY AA1850S SOT23L Tape & Reel 3,000ea MARK CHART 1850 XXXS ■ PACKAGE DIMENSIONS ©Copyright Agamem Microelectronics Inc. 5 www.agamem.com.tw 2008/4/8 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. Agamem Microelectronics Inc. PRELIMINARY AA1850 HIGH-SIDE CURRENT MONITOR ■NOTES ON USE • The specifications for the product described in this document are for reference only. Upon actual use, therefore, please request that specifications to be separately delivered. • The application circuit examples explain typical applications of the products, and do not guarantee the success of any specific mass-production design. • Application circuit diagrams and circuit constants contained herein are shown as examples of standard use and operation. Please pay careful attention to the peripheral conditions when designing circuits and deciding upon circuit constants in the set. • Take account of common impedance when designing the earth line on a printed wiring board. ©Copyright Agamem Microelectronics Inc. 6 www.agamem.com.tw 2008/4/8 AGAMEM MICROELECTRONICS INCOPERATION RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. AGAMEM DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCTS OR CIRCUIT DESRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS.